Entryway systems used in building construction generally include a pair of vertically extending door jambs and a head jamb that frame the entryway and receive a hinged door panel. An elongated threshold assembly is attached at its ends to the bottoms of the door jambs and spans the bottom of the entryway. Many modern threshold assemblies include a frame defining an upwardly-open channel from which a sill slopes outwardly and downwardly. A threshold cap is disposed in the upwardly open channel and underlies a closed door mounted in the entryway. The threshold cap usually is manually adjustable (using, for example, screw mechanisms) in a vertical direction to engage and form a seal with the bottom of the door panel or a flexible sweep attached thereto.
For years, manufacturers of threshold assemblies for entryway systems have struggled with preventing the leakage of incidental rain water beneath the threshold, in order to avoid rainwater causing rot to the underlying sub floor. One location where such incidental leakage is a problem is between the threshold cap and the underside of a door panel or door sweep. In this regard, houses can settle after construction, thus compromising the weathersealing of the door panel due to movement of the mating components from their intended position. Homeowners must then be able to vertically adjust the threshold cap manually in order to correct this issue, which can be difficult to properly achieve. Furthermore, cap plugs used to address these issues placed in adjustment hardware holes can interfere with the sealing of the threshold cap to the underside (e.g., the bottom of the door) of the door panel.
Another location where such incidental leakage is a problem is along the gap between a forward wall of the upwardly open channel of the frame and the threshold cap that rides in the channel. This region poses a particular leakage problem because it is exposed to the elements on the outside of the entryway and, in a blowing rain for example, rainwater can be forced by several hydrodynamic mechanisms into the gap. When this happens, water can collect in the channel under the threshold cap, from where it flows to the ends of the threshold assembly and onto the sub floor below.
A variety of attempts to stem leakage along the gap between the threshold cap and its channel have been made over the years. For example, some threshold assemblies include an upstanding dam that forms the upper part of the outside channel wall. It is also common where plastic threshold caps are used to form the threshold cap with an overlapping tongue along its outside edge that overlaps the dam to prevent leakage of rainwater from the top of the threshold cap directly into the gap between the forward edge of the cap and its channel.
The various techniques used in the past to seal the gap between a threshold cap and its channel have generally been less than successful. For example, flexible bellows-type seals tend to harden, shrink and crack over time, allowing water to seep directly through the bellows and into the channel. Where flexible fins are used to create the seal, dirt can accumulate between the fin and the surface of the threshold cap, breaking the seal. In addition, in cases where the entryway system may not be installed on a perfectly level surface, the threshold assembly can be racked to the extent that the fin separates from the threshold cap, resulting in severe leaks and an unsightly appearance. The seal also can be affected by the natural differential thermal expansion and contraction experienced by the various different materials of the assembly. Even with plastic threshold caps with dams and overlapping tongues, leakage still can occur due to the capillary effect between the tongues and the dams.
Accordingly, a need exists for an entryway system that includes a door entryway system and threshold assembly that improves management of water, both incidental and non-incidental, entering the threshold assembly.